The field of microfluidics has the potential to provide a number of products to better everyday life, but is still not well understood. In previous research performed in the field, microfluidics has been shown to exhibit behavior different from what would be expected through normal pipe flow theory. While some research has shown that fluid flow through microchannels does conform to the theoretical flow mechanics, and thus can be predicted and understood through use of well-known relations; other research performed has indicated that fluid flow through microchannels experiences higher or lower pressure losses than would be expected with macro scale theory. This work strives to further explore and explain this anomaly by focusing on simple straight rectangular channels of varying hydraulic diameters from 24 µm to 88 µm, in order to form a more basic understanding for fluid flow in microchannels. Water was pumped through each of these channels at a number of different flow rates, and the static pressure was measured in two locations, a set length apart. The measured pressure loss over this length for each flow rate was then recorded and analyzed to provide relations between pressure loss and hydraulic diameter. Through the data obtained in this study, microfluidic flow of Reynolds numbers greater than 40 and in channels as small as 48 µm in diameter experienced pressure losses predicted from macroscale theory. Below these values, the data was more random, but still showed some conformance to theory. A clear relationship between measured pressure loss and hydraulic diameters over the entire range of channels was also found for two different flow rates. It is hoped that the data obtained will provide a better understanding of microfluidics and pave the way for potential applications to be realized.